抗藥性基因檢測在幽門螺旋桿菌第一線至第三線治療之應用

Abstract

背景:三合一療法是幽門桿菌第一線治療最常使用的處方，但近年來的許多研究顯示此療法在許多國家的治療成功率已降低至80%以下，因此如何提升幽門桿菌的治療成功率是相當重要的課題。此外，在二次治療失敗時，國際幽門桿菌共識會議建議使用依藥物敏感性測試引導之治療，然而幽門桿菌的培養困難、耗時且昂貴。近年來，有許多研究顯示幽門桿菌對抗生素的抗藥性與幽門桿菌的基因突變有相關，其中clarithromycin及levofloxacin的抗藥性分別與23S ribosomal RNA(23S rRNA)及Gyrase A (GyrA) 的基因突變有相關，但檢測抗藥性基因突變是否能引導幽門桿菌第三線的根除治療目前仍不清楚。 假說: 我們假設含levofloxacin 的三合一治療以及系列性四合一療法在幽門桿菌第一線治療的療效優於三合一療法，gyrA 與 23S rRNA 的突變分別會影響含levofloxacin 的三合一治療以及含clarithromycin的系列性四合一療法之療效，而檢測檢測抗藥性基因突變可以有效引導幽門桿菌第三線的治療。 目的: 基於上述理由，我們想評估在台灣地區較為適當的第一線治療策略，以及探討抗藥性基因對於療效的影響因子，同時也將評估依抗藥性基因檢測在引導幽門桿菌第三線治療的療效。 方法: 因此我們進行了下列的流行病學調查與臨床試驗及臨床相關性研究以驗證上述假說: (1)調查台灣的幽門桿菌抗藥性盛行率，並分析抗藥性的相關危險因子; (2) 進行一項交叉性、多中心的隨機分派試驗，比較含levofloxacin與含clarithromycin之三合一治療在幽門桿菌第一線及第二線之療效; (3) 進行一項多中心、開放性的隨機分派試驗，比較四合一系列性療法10天及14天與將三合一療法14天在幽門桿菌第一線治療的療效，並進一步進行決策分析探討三種策略在不同抗生素抗藥性盛行區域之療效差異; (4) 使用研究(2)所收集之菌株，評估抗藥性基因檢測是否可以預測含levofloxacin三合一治療之療效; (5)評估含高劑量質子幫浦抑制劑及levofloxacin的系列性四合一療法在幽門桿菌第二線治療之療效及安全性;(6)評估抗藥性基因引導之系列性四合一療法在幽門桿菌第三線治療之療效。 結果: 在1464株菌株中，幽門桿菌對於clarithromycin，levofloxacin，amoxicillin，metronidazole，及tetracycline的初級抗藥性盛行率分別為10.6%，9.0%，2.4%，25.5%，及2.3%，但蘭嶼的菌株對於clarithromycin，levofloxacin，及metronidazole的抗藥性則顯著的低於台灣其他地區。在研究(2)的432位病人中，我們的結果顯示傳統的治療順序：使用clarithromycin作為第一線治療，失敗時再以含levofloxacin的三合一作為救援治療，其療效顯著的高於相反順序的療效。在研究(3)的900位病人中，我們的結果顯示系列性四合一療法治療14天的療效優於三合一療法14天，而三種療法的療效都會受到clarithromycin抗藥性的影響，而系列性四合一療法的療效也會受到metronidazole的抗藥性影響。在統計敏感性分析中，我們發現除了在clarithromycin抗藥性盛行率極低且metronidazole抗藥性盛行率極高的地區之外，系列性四合一療法14天的療效皆優於三合一療法14天，而系列性四合一療法10天的療效除了在clarithromycin抗藥性盛行率較低且metronidazole抗藥性盛行率較高的地區之外，也皆優於三合一療法14天。這個研究結果支持將系列性四合一療法做為第一線治療。在研究(4)的328位病人中，我們發現 GyrA及23S rRNA的突變可用來預測治療結果。在研究(5)的142位病人中，結果顯示含高劑量質子幫浦抑制劑與levofloxacin 的系列性四合一療法在第二線治療可以達到95%的成功率。在研究(6)的135位病人中，我們發現利用抗藥性基因型選擇治療處方的整體治療成功率為82%，證實了利用簡單的分子檢測技術，可以有效引導幽門桿菌之治療。 結論：我們的研究顯示含levofloxacin的三合一治療療效低於含clarithromycin 的三合一治療，而將含clarithromycin的三合一治療延長到14天療效也低於系列性四合一治療14天之根除率，因此我們的結果支持將系列性治療14天列為幽門桿菌第一線的標準治療。若第一線治療失敗時，含levofloxacin的系列性四合一治療可以作為三合一或是系列性四合一治療失敗病患的救援治療。而抗藥性基因型的測定，不但可以做為幽門桿菌抗藥性盛行率監測的工具，也可以做為預測治療效果的預測因子，更可以做為引導治療的依據。

Background: The eradication rate of clarithromycin-based triple therapy for Helicobacter pylori has fallen below 80% in many countries. Although several strategies have been proposed to increase the eradication rate, the optimal strategy remains to be determined. Treatment of refractory H. pylori infection is also challenging in clinical practice. Mutations in 23S ribosomal RNA (23S rRNA) and gyrase A (gyrA) have been shown to be associated with clarithromycin and levofloxacin resistance of H. pylori. However, whether the determination of genotypic resistance can guide the treatment of refractory H. pylori infection has not been reported. Objectives: We aimed to assess the optimal strategy in the first line eradication therapy for H. pylori in Taiwan and assess the impact of genotypic resistance on the eradication rates. We also aimed to evaluate the efficacy of genotypic resistance guided therapy in the third line treatment of refractory H. pylori infection. Methods: In order to address the above issues, we conducted one surveillance program, four clinical trials, and one association study. Part 1 was a multicenter surveillance program of the prevalence of antibiotic resistance of H. pylori in Taiwan. Part 2 was a randomized trial with crossover design to assess the efficacies of levofloxacin-based and clarithromycin-based triple therapies in the first-line and second-line treatments. Part 3 was a multicenter, randomized trial to compare the efficacy of suential therapy for 10 and 14 days versus triple therapy for 14 days in the first line treatment. Part 4 was a post hoc analysis to assess the associations of genotypic resistance and treatment outcomes. Part 5 was a multicentre single arm trial to assess the efficacy of modified sequential therapy containing levofloxacin in the second-line therapy. Part 6 was a multicentre single arm trial to assess the efficacy of genotypic resistance-guided sequential therapy in the third-line treatment. Results: Of the 1464 strains, we found that the primary resistance of clarithromycin, levofloxacin, amoxicillin, metronidazole, and tetracycline were 10.6%, 9.0%, 2.4%, 25.5%, and 2.3%, respectively. The primary resistance rates were significantly lower in Eastern Taiwan than in other regions for clarithromycin, levofloxacin, and metronidazole. We showed that the overall eradication rates of CAL followed by LAL were better than the reverse sequence in both the ITT analysis (93% vs 85.3%, p=0.01).The eradication rates for sequential therapy for 14 days (S-14), sequential therapy for 10 days (S-10), and triple therapy for 14 days (T-14) were 90•7% (272/300, 95% CI 87•4%-94•0%), 87•0% (261/300, 95% CI 83•2%-90•8%), and 82•3% (247/300, 95% CI 78•0%-86•6%) in the ITT analysis, respectively. S-14 was superior to T-14 (number needed to treat 12, 95% CI 7•2-34•5, p=0•003). Their efficacies were all affected by clarithromycin resistance. The efficacies of S-14 and S-10 were affected by metronidazole resistance. Sensitivity analyses showed that the sequential therapy appeared to be more efficacious than triple therapy for 14 days in all regions, except in areas with concomitantly low clarithromycin and high metronidazole resistance. The eradication rates in strains with and without gyrA mutations were 41.7% and 82.7%, respectively (P= 0.003). The eradication rate of modified sequential therapy containing levofloxacin and high dose esomeprazole was 95.1% (135/142) in the second line treatment. The eradication rate of genotypic resistance guided sequential therapy was 80.7% (109/135), which indicated that a simple molecular method guided therapy can achieve a high eradication rate in the third-line treatment. Conclusion: The results collectively support the use of clarithromycin-based sequential therapy in the first line therapy. Modified sequential therapy containing levofloxacin and genotypic resistance guided sequential therapy can be used as rescue therapies in the second and third line treatment of H. pylori infection.